Parking brake control valve

ABSTRACT

A parking brake hand control valve assembly wherein an operating shaft is movable in one direction to transmit fluid pressure through said valve from a first source and movable further in the same direction to transmit fluid pressure through said valve from a second source and a shuttle valve assembly precludes loss of pressure from said first source and the brake system to said second source.

United States Patent 1 Klimek [451 Sept. 18,1973

PARKING BRAKE CONTROL VALVE inventor: Boleslaw Klimek, Des Plaines, Ill.

The Berg Manufacturing Company, Des Plaines, 11].

Filed: Oct. 4, 1971 Appl. No.: 186,290

Related Application Data Continuation-impart of Ser. No. 161,176, July9, 1971, abandoned.

Assignee:

[1.8. CI. 303/71 Int. Cl B60t 13/22 Field of Search 303/71; 137/630.19

References Cited l I UNITED STATES: PATENTS 3,224,815 12/1965 Horovvitz303/71 3,572,846 3/1971 Cruse 303/71 3,532,396 10/1970 Carton 303/713,419,315 12/1968 Bueler 303/71 3,107,126 11/1963 Valentine 303/71Primary Examiner-Lloyd L. King Attorney-Howard T. Markey et al.

[57] ABSTRACT 9 Claims, 2 Drawing Figures SUMMARY or THE INVENTION Thisapplication is a continuation-in-part of application Ser. No. 161,176,filed July 9, 1971, now abandoned, and entitled Parking Brake ControlValve."

This invention relates to vehicle brake systems and particularly toparkingbrake systems usable on tractor trailer vehicles.

Such parking brake systems normally employ springapplied, fluidpressure-released v brake actuators and both a normal and an auxiliaryor protected source of fluid pressure. It is, accordingly, one purposeof the invention to provide a hand control valve available tothe vehicleoperator for manual operation, which valve shall be movable in onedirection to evacuate-such actuators and permit the springs therein toapply the vehicle brakes and movable in the opposite direction a firstdistance to supply fluid pressure to said actuators from said normalsource and movable a further distance in said opposite direction tosupply fluid pressure to said actuator from said auxiliary source.

Anotherpurpose is to provide a valve of the type described above whichshall be of maximum simplicity and economy in manufacture and use.

Anotherpurpose is to provide a valve of the type described above whichshall be composed of a minimum number of parts.

Another purpose is to provide a valve of the type described having apositive mechanical contact means insuring availability of fluidpressure through said valve from said auxiliary source.

Another purpose is to provide such a control valve having an isolatedvalve means for supplying pressure from an alternate pressure source.

Another pressure is to provide a control valve of the type described fordual-source systems which includes means precluding loss of fluidpressure from the first fluid pressure source or.from the parking brakesystem in response to failure of pressure at the alternate source. I I

Other purposes may appear from time to time during the course of thespecification and claims. i

. BRIEF DESCRIPTIONAOF THE DISCLOSURE,

The invention isillustrated more orless diagrammatically in theaccompanying drawings wherein:

I haust outlet Sand an opposite valve face 17 municates with outlet 2through passage 11. Inlet 4 communicates with outlet 2 through passage12 and with exhaust outlet 5 through passage 11 and chamber 'A firstvalve member 15 is reciprocal in chamber 6 and carries first valve face16 in position to close expositioned to close passage 8.

A second valve member 20 is yieldingly urged, as by spring 21, intoposition closing passage 12. It will be observed that the fvalve member20 is reciprocal in a chamber 22 communicating with inlet 4 andproviding a fluid pressure receiving area behind valve member 20.

Reciprocably slidable in the housing 1 is a valve operating meansgenerally indicated by the numeral 25. Means 25 includes a shaft portion26 of relatively limited diameter and a shaft portion 27 of greaterdiameter. The portion 27 carries seal means 28 movable between anonsealing position within the enlarged cham ber area 10 and a sealingposition within the normal FIG. 1 is a side elevation in partial crosssection; and

F1012 is a detailed view illustrating a modified ver sion of a portionof the structure of FIG. 1.

Referring now to FIG. 1, the numeral 1 generally designates a valvehousing. Indicated at 2 is a fluid pressure outlet port provided forconnection with suitable conduits to deliver fluid pressure to the brakeactuators of the vehicle. Indicated at 3 is afluid pressure inlet portprovided forreception of fluid pressure from a normal fluid pressuresource indicated in FIG. 1 as source A. p

A second fluid pressureinlet port 4 is provided for connection with anauxiliary or protected tank or reservoir of fluid pressure indicated inFIG. 1 as source B. An exhaust outlet port 5 is provided to communicateaflrst valve chamber 6 with atmosphere. A second chamber 7 communicates.through passage 8 with chamber 6 and at its opposite end through passage9 with inlet 3, the chamber 7 being expanded or enlarged as indicated at10 adjacent passage 9. Chamber 6 comchamber area 7 between passages 9and 8 to seal the same against communication.

A first yieldingmeans 30 of predetermined force is positioned in chamber7 and engages housing 1 and enlarged shaft portion-27 to urge the means25 rearwardly or outwardly of housingl into the position shown inFIG. 1. A second yielding means 31, of somewhat greater force, engagesthe enlarged shaft portion 27 and the valve member 15 to urge the samein opposite directions.

Shaft portion 26 extends slidably through a central bore in member 1 5,as indicated at 32. A shoulder 33 is carried by shaft portion 26beyondmember 15 to limit retrograde movement of shaft portion 26 with respectto valve 15 and seal means 34 is carried by shaft portion 26 forengagement with'the bore of valve member 15. Shaft portion, 26 has adistal portion slidably and sealingly reciprocal in a central bore 35 ofhousing 1, theend surface of shaft portion 26 being positioned foroperating contact with valve member 20 when the shaft 26 has traversed asufficient distance forwardly or inwardly into housing 1.

Referring now to FIG. 2,, it will be understood that the structuretherein illustrated replaces passage 12, valve member 20 and chamber22', the inlet 4 being conveniently repositioned with respect tohousing 1. A shuttle piston is urged by spring 121 within a chamber 122andupw ardly, as the parts are shown, against circumferentially spacedlegs or stop means 123 within which the distal portion of shaft portion26 is located when the parts are in the position shown in FIG. 2.

Positioned beneath shuttle piston 120 and in inlet 4 is a spoke orwebwasher having openings spaced about a central abutment14l.

Within a chamberin shuttle piston 120 a shuttle valve member 142 isfreely reciprocal and carries an ber 142 for closing, respectively andalternatively, passages 144 and 146 to preclude flow of fluid pressurefrom chamber 6 to the source B below a predetermined pressure level andpreclude flow of fluid pressure from source B into chamber 6 or outlet 2above said pressure a level.

The use and operation of the invention are as follows:

As illustrated in FIG. 1, the control valve assembly of the invention isin its brakes-n position, the parts being urged thereinto by spring 30.In such position the outlet 2, and thus the brake actuators of the brakesystem, are exhausted to atmosphere through passage 11, chamber 6 andoutlet 5. Valve face 17 seals inlet 3 and valve 20 seals inlet 4 againstloss of pressure to atmosphere.

When the operator desires to release the brakes and thus to permitvehicle movement, the operator merely presses forward on means 25, asuitable handle element (not shown) being provided thereon externally ofhousing 1. Since spring 31 is of a force greater than that of spring 30,forward movement of means 25 is effective to overcome spring 30 and yet,through the mediacy of spring 31, to move valve member 15 into positionclosing exhaust outlet 5 and opening communication of normal fluidpressure inlet 3 with outlet 2 through passage 9, chamber 7, passage 8,chamber 6 and passage 1 1.

Limited inward movement of means 25 sufficient to seat valve and openpassage 8 is insufficient to-bring seal means 28 into sealing contactwith the normal inner diameter of chamber 7. The fluid pressure suppliedat inlet 3, operative now against the larger diameter of valve 15, issufficient to retain valve means 15 in its position closing outlet 5 andcommunicating inlet 3 I with outlet 2, spring 30 being of insufficientforce to overcome the normal predetermined pressure at inlet 3 whenvalve 15 is in said position.

Said inward movement of means 25 is insufficient, however, to bring thedistal end of shaft portion 26 into opening engagement with valve member20. Hence the auxiliary or protected tank indicated as source B remainsindependent and unaffected.

Should the vehicle operator thereafter wish to apply the brakes of thevehicle, in any emergency or for parking purposes, the operator merelydraws the means 25 rearwardly or toward himself, the shoulder 33engaging valve 15 and moving it into the position shown, exhaustingoutlet 2 and thus the brake actuators (not shown) to atmosphere andpermitting the springs in said actuators to apply the brakes.

Similarly, a failure of fluid pressure at inlet 3 results automaticallyin return of the parts to the position shown, through the mediacy ofspring 30, to apply the brakes of the vehicle. Should the vehicleoperator then wish to release the brakes, pressure at inlet 3 beingabsent or insufficient, to permit movement of the vehicle for examplefrom the highway, the operator merely presses the means 25 to its fullovertravel position inwardly of housing 1, the operator overcoming theresistance of spring 31 and moving the end of shaft portion 26 intocontact with valve member 20 to open it against the action of spring 21.Thereupon fluid pressure will flow from source B to outlet 2 and will betransmitted through the valve of the invention to the brake actuators torelease the brakes and permit vehicle movement. In the initial portionof such inward movement of means 25 the valve 15 will have been movedinto position closing exhaust outlet 5. Similarly, the continued inwardmovement of means 25 brings seal 28 into sealing contact with the normaldiameter of chamber 7 to close passage 9 and inlet 3 againstcommunication with outlet 2.

Since fluid pressure from source B would, in such event, remain on bothsides of member 20, withdrawal of shaft 26 permits spring 21 to closevalve member 20 and the operator must therefore hold means 25 inwardlyto retain the member 20 in open position for as long as the operatordesires that the brakes be released. Upon the operators relaxation ofinward pressure on means 25, the parts will be returned to the positionshown in FIG. 1 and the brake actuators will be exhausted through outlet2, passage 11, chamber 6 and exhaust outlet 5 to again apply the brakes,the member 20 closing to protect the source B against loss of pressure.

In the variant form of the invention wherein the lower portion of thestructure shown in FIG. 1 is replaced by that shown in FIG. 2, means areprovided for preventing the loss of all of the fluid pressure from thetotal system in the event of a leak or diminution of pressure in thealternate source B. In such event fluid pressure would not be availableto release the spring brakes in an emergency situation. A predeterminedpressure level is established which may, for example, be 60 psi. When,for example, the pressure in the system, and thus in chamber 6, isgreater than 60 psi, the shuttle will be moved against the action ofspring 121, or downwardly as the parts are shown, to bring extension 143into contact with abutment stop 141 to open a path through the assembly120,142 and to permit flow of fluid pressure from chamber 6 to thesource B to fill the same. At pressures in chamber 6 below 60 psi theseal 147 precludes such flow of fluid pressure from chamber 6 to sourceB. Valve member 142 operates as a double check valve to protect alsoagainst the flow of high pressure in source B into the system. The seal148 being held closed against passage 146 by such high pressure butbeing operable manually by the vehicle operator pressing inwardly onshaft 26 for its full travel to bring the same into contact withextension 145 precisely as described above with respect to the form ofFIG. 1. Thus the action of the vehicle operator is identical under allof the circumstances described with the devices of both FIGS. 1 and 2,the latter including structure effective to preclude loss of fluidpressure to a diminished or depleted alternate source B.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. In a hand control valve for fluid pressure brake systems, a valvehousing, a normal fluid pressure inlet in said housing, a fluid pressureoutlet in said housing, an exhaust outlet in said housing, an alternatefluid pressure inlet in said housing, a shaft reciprocal in said housingand extending externally thereof for manual operation, a first valvemember slidable on said shaft and having a larger valve face positionedfor closing said exhaust outlet at one position of said first valvemember and a second, smaller valve face positioned for closingcommunication between said first inlet and said pressure outlet inanother position of said first valve member, yielding means urging saidshaft outwardly of said housing and said first valve member toward saidother position, an abutment on said shaft and engageable with said firstvalve member in response to outward movement of said shaft whereby saidfirst valve member is urged by said first yielding means into said otherposition of said first valve member, a second valve member controllingcommunication between said alternate pressure inlet and said pressureoutlet, said first valve being movable into said one position inresponse to inward movement of said shaft a predetermined distance, saidshaft having a distal portion positioned for operating contact with saidsecond valve member in response to further inward movement of saidshaft, and a second yielding means, of greater force than that of saidfirst yielding means and engaging said shaft and said first valve memberto urge the same in opposite directions.

2. The structure of claim 1 characterized by and including sealing meanscarried by said shaft and movable into a position sealing said firstinlet against communication with said fluid pressure outlet and saidexhaust outlet when said shaft has moved a predetermined positioninwardly of said housing.

3. The structure of claim 2 wherein said housing includes a chambersurrounding said shaft, said chamber includes an enlarged diameterportion, said first pres sure inlet communicates with said enlargedportion and said shaft sealis positioned for movement between anonsealing position with said enlarged portion and a sealing positionwithin said chamber, said shaft seal being movable into said sealingposition in response to said further inward movement of said shaft.

4. The structure of claim 1 wherein said first and second yielding meanssurround said shaft and said first yielding means surrounds said secondyielding means.

5. The structure of claim 1 characterized by and including a thirdyielding means urging said second valve member into a position closingsaid pressure outlet against communication with said alternate pressureinlet in the absence of operating contact between said second valvemember and said shaft and a chamber surrounding said second valve memberand providing fluid pressure from said alternate inlet to urge saidsecond valve member into said closing position.

cation respectively between said first and second inlets with saidpressure outlet, said first valve member controlling communication ofsaid pressure outlet with said exhaust outlet, an operating shaftmovable in said housing between a rear position, a first forwardposition and a second forward position, a spring overtravel connectionbetween said shaft and said first valve member and effective to movesaid first valve member in response to movement of said shaft from saidrear to said first forward position,.said spring connection urging saidshaft and first valve member in opposite directions and beingineffective to prevent movement of said shaft relative to said firstvalve member from said first to said second forward position, said shafthaving a portion movable into operating contact with said second valvemember when said shaft is moved from said first to said second forwardposition. 1

7. The structure of claim 6 characterized by and including a sealcarried by said shaft and movable into sealing engagement with saidhousing to seal said first inlet as said shaft is moved from said firstto said second forward position.

8. The structure of claim 6 wherein said second valve member includes ashuttle assembly, said shuttle assembly including a valve elementmovable in response to fluid pressure at said outlet above apredetermined level into a position opening said second inlet to flow ofpressure from said outlet to said second inlet and movable in responseto an excess of fluid pressure at said second inlet over that in saidoutlet to preclude the flow of fluid pressure from said second inlet tosaid outlet.

9. The structure of claim 8 wherein said valve element is operable bysaid shaft to permit flow of fluid pressure from said second inlet tosaid outlet.

1. In a hand control valve for fluid pressure brake systems, a valvehousing, a normal fluid pressure inlet in said housing, a fluid pressureoutlet in said housing, an exhaust outlet in said housing, an alternatefluid pressure inlet in said housing, a shaft reciprocal in said housingand extending externally thereof for manual operation, a first valvemember slidable on said shaft and having a larger valve face positionedfor closing said exhaust outlet at one position of said first valvemember and a second, smaller valve face positioned for closingcommunication between said first inlet and said pressure outlet inanother position of said first valve member, yielding means urging saidshaft outwardly of said housing and said first valve member toward saidother position, an abutment on said shaft and engageable with said firstvalve member in response to outward movement of said shaft whereby saidfirst valve member is urged by said first yielding means into said otherposition of said first valve member, a second valve member controllingcommunication between said alternate pressure inlet and said pressureoutlet, said first valve being movable into said one position inresponse to inward movement of said shaft a predetermined distance, saidshaft having a distal portion positioned for operating contact with saidsecond valve member in response to further inward movement of saidshaft, and a second yielding means, of greater force than that of saidfirst yielding means and engaging said shaft and said first valve memberto urge the same in opposite directions.
 2. The structure of claim 1characterized by and including sealing means carried by said shaft andmovable into a position sealing said first inlet against communicationwith said fluid pressure outlet and said exhaust outlet when said shafthas moved a predetermined position inwardly of said housing.
 3. Thestructure of claim 2 wherein said housing includes a chamber surroundingsaid shaft, said chamber includes an enlarged diameter portion, saidfirst pressure inlet communicates with said enlarged portion and saidshaft seal is positioned for movement between a nonsealing position withsaid enlarged portion and a sealing position within said chamber, saidshaft seal being movable into said sealing position in response to saidfurther inward movement of said shaft.
 4. The structure of claim 1wherein said first and second yielding means surround Said shaft andsaid first yielding means surrounds said second yielding means.
 5. Thestructure of claim 1 characterized by and including a third yieldingmeans urging said second valve member into a position closing saidpressure outlet against communication with said alternate pressure inletin the absence of operating contact between said second valve member andsaid shaft and a chamber surrounding said second valve member andproviding fluid pressure from said alternate inlet to urge said secondvalve member into said closing position.
 6. A hand control valveincluding a housing, a first inlet and a second inlet in said housing, apressure outlet and an exhaust outlet in said housing, independent firstand second valve members controlling communication respectively betweensaid first and second inlets with said pressure outlet, said first valvemember controlling communication of said pressure outlet with saidexhaust outlet, an operating shaft movable in said housing between arear position, a first forward position and a second forward position, aspring overtravel connection between said shaft and said first valvemember and effective to move said first valve member in response tomovement of said shaft from said rear to said first forward position,said spring connection urging said shaft and first valve member inopposite directions and being ineffective to prevent movement of saidshaft relative to said first valve member from said first to said secondforward position, said shaft having a portion movable into operatingcontact with said second valve member when said shaft is moved from saidfirst to said second forward position.
 7. The structure of claim 6characterized by and including a seal carried by said shaft and movableinto sealing engagement with said housing to seal said first inlet assaid shaft is moved from said first to said second forward position. 8.The structure of claim 6 wherein said second valve member includes ashuttle assembly, said shuttle assembly including a valve elementmovable in response to fluid pressure at said outlet above apredetermined level into a position opening said second inlet to flow ofpressure from said outlet to said second inlet and movable in responseto an excess of fluid pressure at said second inlet over that in saidoutlet to preclude the flow of fluid pressure from said second inlet tosaid outlet.
 9. The structure of claim 8 wherein said valve element isoperable by said shaft to permit flow of fluid pressure from said secondinlet to said outlet.